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      THE INTERNATIONAL MARSWATCH ELECTRONIC NEWSLETTER
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                     Volume 3; Issue 4 
                     February 13, 1998
                     Circulation: 1495

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Here is the latest colorful installment of the MarsWatch news, 
complements of A.L.P.O. Mars recorders Dan Joyce and Dan Troiani. 

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MarsWatch News: February 1998
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Compiled by Dan Joyce (djoyce@triton.cc.il.us) and 
            Dan Troiani (dtroiani@triton.cc.il.us), 
            Association of Lunar and Planetary Observers

GLOBAL SURVEYOR UPDATE

Despite the initial difficulty in achieving desired orbit owing to a weakened 
solar panel, the Global Surveyor Mission has revealed its prowess.  Spacecraft 
power constraints may force its camera to temporarily shut down soon, but the 
imagery so far has been a major revelation.  Valles Marineris has been found 
to be stratified to an extent that suggests Mars' geological distant past was 
more active than had been previously thought by several orders of magnitude.  
There is even a suggestion of the coming and passing of a sea across the 
terrain fairly high in the strata.  Layering of the kind seen generally in 
the images could have formed from sedimentary deposits or episodes
of volcanism.  In neither case was Mars expected to be so active, especially 
for the amount of time that seems to have elapsed in their formation and how 
recently the last deposit seems to have occurred.  The resemblance to the 
Grand Canyon in Arizona is remarkable.

Modern computer legerdemain comes into play because distortions introduced by 
the camera lens and the awkward aspect of the spacecraft motion can be 
"fitted" to exactly describe what would be seen from a specific point in the 
orbit using an elaborate averaging technique.  One image in particular is of 
Nanedi Vallis, a sinuous canyon in Xanthe that appears to have resulted from 
a continuous water flow rather than an abrupt single event, at least that 
seems to be inferred from apparent downcutting features.  There is also 
evidence of slumping, so both processes may have acted in tandem to produce 
this valley.  This image has resolution to a mere 39 feet, and was the fourth 
taken during the spacecraft's 87th orbit.  The other image highlight is a 
close-up of Valles Marineris, taken as the third image during the 80th orbit 
(on the evening of January 1st).  It is here that the sedimentary processes 
are especially prominent.  The detail is comparable to that of the Nanedi 
Vallis image.

In summary, yet another revolution in our thinking of the Red Planet must 
transpire.  Evidently the findings in ALH84001 were just a precursor and 
probably no accident.  We can safely look forward to images over the coming 
months that will tantalize even more - of such resolution as to not fail to 
reveal transcending new visions to challenge our already shattered 
preconceptions of what Mars is all about.  The need to explore further will 
be enhanced, not diminished, by the findings of Global Surveyor, an intrepid 
if inexpensive explorer of a planet whose lore spans the imaginations of 
generations.

THE 1996-97........ 98 MARS APPARITION

As if to mimic Ted Stryk, Jeff Beish joined Don Parker at the latter's 
observing station and did a Mars sketch on January 21st (!) with Mars all 
of 4.3 arcseconds and in deep twilight just a few degrees above the southwest 
horizon.  But true to form, South Florida laminar flow held and Syrtis Major 
and the SPC showed up despite.  
Why did we return from the Winter Star Party?!?!?

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Useful WWW sites:
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Latest MGS images: 
 
http://www.msss.com/mars/global_surveyor/camera/images/index.html

Main MGS Home Page:  

http://mars.jpl.nasa.gov/mgs/index.html

Pathfinder Home Page:

http://mars.jpl.nasa.gov/default.html

JPL Mars Missions Page

http://www.jpl.nasa.gov/mars

Mars-98 MVACS Science Payload Home Page:

http://mvacs.ess.ucla.edu/index.html

Mars-01 Athena Science Payload

http://astrosun.tn.cornell.edu/athena/index.html

A.L.P.O. Mars observations: 

http://www.lpl.arizona.edu/~rhill/alpo/mars.html

1996-97 Marswatch highlights: 

http://mpfwww.jpl.nasa.gov/mpf/marswatch.html

1996-97 Marswatch ftp site: 

ftp://marsnt3.jpl.nasa.gov

MarsNet:  

http://astrosun.tn.cornell.edu/marsnet/mnhome.html

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I will continue to maintain the email distribution list as well
as the various Cornell and JPL Marswatch-related WWW archives. If
you are receiving duplicate copies of this mailing, or you want
your name removed from the distribution list, please send me email.
--Jim

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Jim Bell
Cornell University
Department of Astronomy
Center for Radiophysics and Space Research
424 Space Sciences Building
Ithaca, NY 14853-6801
phone: 607-255-5911; fax: 607-255-9002
email: jimbo@marswatch.tn.cornell.edu
WWW: http://marswatch.tn.cornell.edu
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